using System;

namespace YAF.Lucene.Net.QueryParsers.Classic
{
    /*
     * Licensed to the Apache Software Foundation (ASF) under one or more
     * contributor license agreements.  See the NOTICE file distributed with
     * this work for additional information regarding copyright ownership.
     * The ASF licenses this file to You under the Apache License, Version 2.0
     * (the "License"); you may not use this file except in compliance with
     * the License.  You may obtain a copy of the License at
     *
     *     http://www.apache.org/licenses/LICENSE-2.0
     *
     * Unless required by applicable law or agreed to in writing, software
     * distributed under the License is distributed on an "AS IS" BASIS,
     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     * See the License for the specific language governing permissions and
     * limitations under the License.
     */
	
	/// <summary> 
    /// Describes the input token stream.
    /// </summary>
#if FEATURE_SERIALIZABLE
    [Serializable]
#endif
	public class Token
	{
		
		/// <summary> 
        /// An integer that describes the kind of this token.  This numbering
		/// system is determined by JavaCCParser, and a table of these numbers is
		/// stored in the file ...Constants.java.
		/// </summary>
		public int Kind { get; set; }

        /// <summary>The line number of the first character of this Token. </summary>
        public int BeginLine { get; set; }
        /// <summary>The column number of the first character of this Token. </summary>
        public int BeginColumn { get; set; }
        /// <summary>The line number of the last character of this Token. </summary>
        public int EndLine { get; set; }
        /// <summary>The column number of the last character of this Token. </summary>
        public int EndColumn { get; set; }

        /// <summary>The string image of the token.</summary>
        public string Image { get; set; }

        /// <summary> 
        /// A reference to the next regular (non-special) token from the input
        /// stream.  If this is the last token from the input stream, or if the
        /// token manager has not read tokens beyond this one, this field is
        /// set to null.  This is true only if this token is also a regular
        /// token.  Otherwise, see below for a description of the contents of
        /// this field.
        /// </summary>
        public Token Next { get; set; }

        /// <summary> 
        /// This field is used to access special tokens that occur prior to this
        /// token, but after the immediately preceding regular (non-special) token.
        /// If there are no such special tokens, this field is set to null.
        /// When there are more than one such special token, this field refers
        /// to the last of these special tokens, which in turn refers to the next
        /// previous special token through its specialToken field, and so on
        /// until the first special token (whose specialToken field is null).
        /// The next fields of special tokens refer to other special tokens that
        /// immediately follow it (without an intervening regular token).  If there
        /// is no such token, this field is null.
        /// </summary>
        public Token SpecialToken { get; set; }

        /// <summary> 
        /// An optional attribute value of the Token.
        /// Tokens which are not used as syntactic sugar will often contain
        /// meaningful values that will be used later on by the compiler or
        /// interpreter. This attribute value is often different from the image.
        /// Any subclass of Token that actually wants to return a non-null value can
        /// override this method as appropriate.
        /// </summary>
        public virtual object Value
	    {
	        get { return null; }
	    }

	    /// <summary> 
        /// No-argument constructor
        /// </summary>
		public Token()
		{
		}
		
		/// <summary> 
        /// Constructs a new token for the specified Image.
        /// </summary>
		public Token(int kind)
            : this(kind, null)
		{
		}
		
		/// <summary> 
        /// Constructs a new token for the specified Image and Kind.
        /// </summary>
		public Token(int kind, string image)
		{
			this.Kind = kind;
			this.Image = image;
		}
		
		/// <summary> 
        /// Returns the image.
        /// </summary>
		public override string ToString()
		{
			return Image;
		}
		
		/// <summary> 
        /// Returns a new Token object, by default. However, if you want, you
		/// can create and return subclass objects based on the value of ofKind.
		/// Simply add the cases to the switch for all those special cases.
		/// For example, if you have a subclass of Token called IDToken that
		/// you want to create if ofKind is ID, simply add something like :
		/// 
		/// case MyParserConstants.ID : return new IDToken(ofKind, image);
		/// 
		/// to the following switch statement. Then you can cast matchedToken
		/// variable to the appropriate type and use sit in your lexical actions.
		/// </summary>
		public static Token NewToken(int ofKind, string image)
		{
			switch (ofKind)
			{
				default:  return new Token(ofKind, image);
			}
		}
		
		public static Token NewToken(int ofKind)
		{
			return NewToken(ofKind, null);
		}
	}
}